for (int i = 0; i < numObjects; i++)
{
    float theta = i * 2 * Mathf.PI / numObjects;
    float x = Mathf.Sin(theta)*radius;
    float y = Mathf.Cos(theta)*radius;
  
    GameObject ob = new GameObject();
    ob.transform.parent = transform;
    ob.transform.position = new Vector3(x, y, 0);  
}